1. Field of the Invention
This invention relates to a novel phosphoric acid ester and a novel detergent composition, and, more particularly, to a phosphoric acid ester represented by the following formula (I): ##STR2## wherein R.sub.1 represents a linear or branched, alkyl or alkenyl group having a C.sub.1- 36 carbon atom content, with or without the hydrogen atom(s) being substituted with fluorine atom(s), or a phenyl group with substituted linear or branched alkyl group(s) having a C.sub.1-15 carbon atom content, R.sub.2 represents an alkylene group having a C.sub.2-3 carbon atom content, R.sub.3 and R.sub.4 independently denote a hydrogen atom or an alkyl group having a C.sub.1-3 carbon atom content, R.sub.5 and R.sub.6 independently denote a hydrogen atom, or an alkyl, alkenyl, or phenyl group with or without the hydrogen atom(s) being substituted with group(s) containing hetero atom(s), excepting for a mercapto group, m is an integer of 0-30, n is an integer of 0-5, M is a hydrogen atom, an alkali metal, an alkali earth metal, an ammonium group, an alkyl amine group, or an alkanol amine group. The invention also relates to a a phosphoric acid ester represented by the following formula (IX): ##STR3## wherein R.sub.7 and R.sub.8 independently denote a hydrogen atom, or an alkyl or alkenyl group, and 1 is an integer of 0-3, and R.sub.1, R.sub.2, R.sub.3, R.sub.4, m, and M have the same meanings as defined above. The invention also is directed to processes for preparing the above phosphoric acid esters, as well as detergent compositions comprising the same.
2. Description of the Background
Phosphoric acid esters are used in wide varieties of fields as detergents, fiber treating agents, emulsifiers, rust inhibitors, liquid ion-exchangers, medicines, or the like.
Among surface active agents currently used as detergents, alkyl sulfates, alkylbenzene sulfonates, .alpha.-olefin sulfonates, and the like tend to make the skin roughened. Because of this, the use of less irritative surface active agents such as phosphoric acid monoesters, acyl glutamates, and the like are attracting a wider popularity.
The rise in the standard of living in recent years, however, demands the development of cosmetics and toiletries which can provide a higher safety and more sophisticated functions to human bodies.
Many types of phosphoric acid ester-type compounds having a quaternary ammonium salt in the molecule, which are called phospholipids, including lecithin, phosphatidyl serine, and the like, are present in living bodies. These phospholipids are widely used because of their surface-active, emulsifying, and physiological characteristics. Compounds having molecular structures analogous to these phospholipids can be presumed to be less irritative to living bodies than monoalkyl phosphate salts. Because of this, many kinds of phospholipid analogous compounds are synthesized. Many of the phospholipid analogous compounds, however, require a multiple steps of reactions for their synthesis, and therefore most of them could be synthesized only at a poor yield [For instance, E. Baer et al., J. Amer. Chem. Soc., 72, 942 (1950) and T. Yamakawa, Lipids, Kyoritsu Publishing Co. (1973)]. In addition, quite a few of them require compounds as raw materials which are difficult to synthesize or involve difficulties in separating the target compounds after the reaction, resulting in a poor production yield. Furthermore, many of the compounds exhibit only insufficient surface activity (For example, Japanese Patent Publication No. 23330/1967, Japanese Patent Publication No. 1654/1973, and U.S. Pat. No. 3,507,937).
In view of this situation, the present inventors have undertaken extensive studies to resolve above problems, and as a result have found that the novel phosphoric acid esters represented by formulae (I) and (IX) can be prepared through a simple process at a high purity and high yield using raw materials which are inexpensive and readily available. The inventors have further found that the novel phosphoric acid esters represented by formulae (I) and (IX) are less irritative to the skin and hair, and exhibits excellent foaming and detergent capabilities. These findings have led to the completion of this invention.